1. Field of the Invention
The present invention, generally, relates to detecting the identity of respective components of an alternating current and, more particularly, relates to identifying a predetermined aspect of the configuration of alternating current at a remote location.
There are many instances in the field when multiple phases are used in a source of electrical power. For example, when an electric motor is to be controlled smoothly, such as in elevators or in the operation of machinery, alternating current is used.
When alternating current is used, it is frequently multiple phases, particularly when more work is to be done. It is the custom to use three phase electricity when the phase is to be multiple, because it is readily generated and is available almost universally.
The identity of phase characteristics relative to each other becomes most important in a three phase alternating current line source, not only at the main service panel but also at each remote service outlet. Several aspects of an alternating current line source, for example, include (1) phase rotation, (2) service configuration and (3) phase rotation identification compared to a known reference.
The control of a three phase device is interrupted when the sequence of the phases is connected incorrectly. Therefore, it becomes most important to be able to identify the characteristics of a three phase, alternating current power source anywhere it is necessary to connect an operating device. Phase identification is important and has intensified, due to utility companies attempting to measure power consumption profiles of equipment in buildings, especially commercial buildings where 3 phase power is common.
2. Description of the Prior Art
With the dramatic increase in use of three phase power, the search has intensified for an effective method and apparatus for identifying phase rotation, phase identification and service configuration at all needed locations.
In 1986, U.S. Pat. No. 4,584,652 issued to Sturza et al. which describes a processor which, when connected to a source, will detect components of a phase error.
In 1987, U.S. Pat. No. 4,636,720 issued to Farr which describes a device to monitor a three phase power source to detect a problem that may develop.
In 1988, U.S. Pat. No. 4,785,251 issued to Akiyama et al. which describes a device to detect frequency and phase differences between an input signal and a generated reference.
While each of these prior efforts may be effective in the intended circumstances, none will perform the needed feats which the present invention so uniquely is adapted to perform. This will become abundantly clear as the description proceeds.